Isolation is a Reaper

Research indicates that perceived social isolation (PSI) is a risk factor for and may contribute to “poorer overall cognitive performance and poorer executive functioning, faster cognitive decline, more negative and depressive cognition, heightened sensitivity to social threats, and a self-protective confirmatory bias in social cognition” (Cacioppo & Hawkley, 2009). PSI also contributes to accelerating the ageing process: Wilson et al. (2007) reported that, after controlling for social network size and frequency of social activity, perceived social isolation is predictive of cognitive decline and risk for Alzheimer's disease. Moreover, the social interactions of individuals who feel socially isolated are more negative and less subjectively

https://en.wikipedia.org/wiki/Social_isola